Erlotinib hydrochloride is the common chemical name of [6,7-bis(2-methoxy-ethoxy)-quinazolin-4-yl]-(3-ethynyl-phenyl) amine hydrochloride, a human epidermal growth factor type/epidermal growth factor receptor (HER1/EGFR) tyrosine kinase inhibitor, and following represents its chemical structure:

Erlotinib hydrochloride is the FDA approved drug for the treatment of non-small cell lung cancer. It has the potential for the treatment and/or prevention of diseases which are associated with tyrosine kinase enzymes such as epidermal growth factor receptors, such as cancer, particularly non small cell lung cancer, colorectal cancer, refractory non small cell lung cancer, pancreatic cancer, ovarian cancer, breast cancer, glioma, head cancer or neck cancer.
In WO 96/30347, the preparation of [6,7-Bis-(2-methoxy-ethoxy)-quinazolin-4-yl]-(3-ethynyl-phenyl)amine hydrochloride (erlotinib hydrochloride) as well as the uses of this compound for the treatment of hyperproliferative diseases have been disclosed. As described in Example 20, the erlotinib hydrochloride was prepared by dissolving the corresponding free base in CHCl3 and ether, and titrated with 1M HCl in ether to precipitate the product as its hydrochloride salt. The obtained product has a melting point of 228-230° C., which is similar to that of polymorph form B of erlotinib hydrochloride, as described in Example 4 of a publication US2004/0162300.
Recently, two different polymorph forms of [6,7-bis(2-methoxy-ethoxy)-quinazolin-4-yl]-(3-ethynyl-phenyl)amine hydrochloride, designated as polymorph form A and polymorph form B, have been disclosed in WO 01/34574. As described in Example 4 and 5 of this publication, pure polymorph form A and pure polymorph form B or a mixture of polymorph form A and form B of erlotinib hydrochloride were made according to its procedures.
The preparation of a third polymorphic form of erlotinib hydrochloride, designed as polymorph form E, has been disclosed in US2004/0162300. As described in Example 1 of this publication, only crystal material (polymorph form E) of erlotinib hydrochloride was obtained.
All of references cited above did not mention or disclose amorphous forms of erlotinib hydrochloride.
The difference in many aspects of solid state properties such as solubility, dissolution and bioavailability of crystal (polymorphic) forms and amorphous forms of a given drug substance has been widely reported. The amorphous forms in a number of drugs exhibit superior dissolution characteristics and in some cases different bioavailability patterns compared to crystalline forms [Konne T., Chem Pharm Bull, 38, 2003 (1990)] were also noticed. For some therapeutic indications one bioavailability pattern may be favored over another. An amorphous form of cefuroxime axietil is good example for exhibiting much higher bioavailability than the crystalline forms, which leads to the selection of amorphous form as the final drug substance for cefuroxime axietil pharmaceutical dosage form development. In addition, since the physical and chemical stability of amorphous form can be improved by making solid amorphous dispersion containing drug substance and a carrier, the amorphous forms of most drug substances are therefore suitable for preparing solid pharmaceutical dosage forms.